v0.5.0

non-backwards compatible with v0.4

This lib will become semver compatible starting with 1.0 - until then, minors may break.

• move to an ObjectEntry enum wrapping objects, which will be either an object or a list of objects. This enables defining a "root" object and accessing it directly as objects.[object-name] where object-name corresponds to a objects/object-name.toml file.
• improve toml parsing speed by 10x